We will continue to study mechanisms by which the ciliary epithelia, ocular vasculature, and aqueous outflow channels maintain intraocular pressure. The ciliary epithelium will be studied under in vitro conditions of culture and their viability and transport properties characterized. Endogenous humoral and pharmacologic influences upon the rate of aqueous humor flow will be measured by clearance techniques. The role of adenyl cyclase will be clarified in this regard. The mechanism of action of adrenergic drugs on intraocular pressure will be studied. An attempt will be made to isolate adrenergic receptors by pharmacologic, chemical and anatomic techniques. Mediators and mediator pathways, especially those involving peptides, associated with ocular irritation will be studied.